A space between two teeth, medically termed a diastema, is a common occurrence that can affect both the appearance and function of a smile. Braces are a highly effective method for correcting these gaps by physically moving the teeth along the dental arch. The process relies on mechanical force and the body’s natural biological response to reposition the teeth into continuous alignment. This orthodontic approach addresses spacing issues of various sizes and causes.
How Braces Mechanically Close Gaps
The movement of teeth during orthodontic treatment is a partnership between the hardware and the body’s biology. Brackets, which are bonded to the teeth, act as handles, while the archwire provides the continuous, gentle force necessary to guide the teeth. This sustained pressure triggers a physiological process called bone remodeling in the jawbone surrounding the tooth roots.
On the side of the tooth where the archwire is pushing, specialized cells called osteoclasts break down the bone tissue. On the opposite side, where the periodontal ligament is stretched, osteoblasts build new bone to fill the resulting space and stabilize the tooth in its new position. This controlled destruction and rebuilding of bone allows the tooth to migrate slowly through the jawbone.
For closing gaps, orthodontists frequently employ specialized elastic chains, often called power chains. These are continuous series of connected elastic rings that replace the individual elastic ligatures on the brackets. Power chains provide a continuous, contracting force that pulls multiple teeth together simultaneously. They are often introduced in the mid-to-late stages of treatment to consolidate any remaining spaces.
Understanding the Different Causes of Dental Gaps
The complexity of treating a diastema often depends on identifying the root cause of the spacing. One of the most common reasons for gaps is a discrepancy between the size of the teeth and the size of the jawbone. If the jaw is relatively large or the teeth are proportionally small, extra space naturally occurs between the teeth.
Gaps can also result from the absence of teeth, a condition known as hypodontia, or from teeth that are undersized, such as peg laterals. Certain habitual behaviors, particularly in childhood, can also force teeth apart over time. These include chronic thumb sucking or an incorrect swallowing reflex called tongue thrusting, where the tongue pushes against the front teeth during swallowing.
Another specific anatomical cause is an oversized labial frenum, the band of tissue connecting the upper lip to the gum line between the two front teeth. If this frenum is thick or extends too far down, it can physically push the central incisors apart, creating a midline gap. When this is the cause, closing the gap with braces may not be sufficient, and a minor surgical procedure might be necessary to address the tissue.
Non-Brace Treatment Alternatives
While braces are highly effective, alternative and less visible options exist for closing spaces between teeth. Clear aligners, such as those made from custom-fitted, transparent plastic trays, are a popular choice for treating mild to moderate spacing issues. These aligners apply gentle, controlled forces to shift the teeth incrementally, similar to braces, but can be removed for eating and oral hygiene.
For very small gaps, a conservative option is composite bonding. This procedure involves applying a tooth-colored resin material to the surface of the tooth and shaping it to fill the space. Bonding can often be completed in a single dental visit and is a relatively affordable treatment for minor cosmetic issues.
Another aesthetic alternative is the use of porcelain veneers, which are thin, custom-made shells that cover the front surface of the teeth. Veneers can close gaps by masking the space and creating the illusion of a full, evenly spaced dental arch. In cases where an oversized frenum is the cause of the gap, a simple surgical procedure called a frenectomy may be performed to reduce the tissue band. This procedure is typically done as a supplement to orthodontic treatment to ensure the gap does not reappear.
Preventing Gap Relapse After Treatment
After the active phase of treatment closes the gaps, the teeth have a strong tendency to drift back toward their original positions, a phenomenon known as orthodontic relapse. This is largely due to the “memory” of the fibers within the periodontal ligament and the elasticity of the gum tissue that surround the teeth. Therefore, the retention phase is a necessary part of gap closure treatment.
Orthodontists prescribe retainers to hold the teeth in their new positions while the surrounding bone and soft tissues stabilize. One type is the fixed or bonded retainer, which consists of a thin wire permanently cemented to the tongue-side surface of the front teeth. This provides continuous, passive stability and is often recommended for cases involving significant gap closure.
Alternatively, removable retainers come in two main forms: clear plastic aligner-style trays or a Hawley retainer made of acrylic and wire. These must be worn exactly as prescribed, often full-time initially and then nightly, to prevent the teeth from shifting. Consistent, long-term retainer wear is the only way to ensure the result of a closed gap is maintained for a lifetime.